Convert a list to a string in C#

I am going to go with my gut feeling and assume you want to concatenate the result of calling ToString on each element of the list.

var result = string.Join(",", list.ToArray());

You could use string.Join:

List<string> list = new List<string>()
{
    "Red",
    "Blue",
    "Green"
};

string output = string.Join(Environment.NewLine, list.ToArray());    
Console.Write(output);

The result would be:

Red    
Blue    
Green

As an alternative to Environment.NewLine, you can replace it with a string based line-separator of your choosing.

String.Join(" ", myList) or String.Join(" ", myList.ToArray()). The first argument is the separator between the substrings.

var myList = new List<String> { "foo","bar","baz"};
Console.WriteLine(String.Join("-", myList)); // prints "foo-bar-baz"

Depending on your version of .NET you might need to use ToArray() on the list first..

If you want something slightly more complex than a simple join you can use LINQ e.g.

var result = myList.Aggregate((total, part) => total + "(" + part.ToLower() + ")");

Will take ["A", "B", "C"] and produce "(a)(b)(c)"

You have a List<string> - so if you want them concatenated, something like

string s = string.Join("", list);

would work (in .NET 4.0 at least). The first parameter is the delimiter. So you could also comma-delimit etc.

You might also want to look at using StringBuilder to do running concatenations, rather than forming a list.

The .ToString() method for reference types usually resolves back to System.Object.ToString() unless you override it in a derived type (possibly using extension methods for the built-in types). The default behavior for this method is to output the name of the type on which it's called. So what you're seeing is expected behavior.

You could try something like string.Join(", ", myList.ToArray()); to achieve this. It's an extra step, but it could be put in an extension method on System.Collections.Generic.List<T> to make it a bit easier. Something like this:

public static class GenericListExtensions
{
    public static string ToString<T>(this IList<T> list)
    {
        return string.Join(", ", list);
    }
}

(Note that this is free-hand and untested code. I don't have a compiler handy at the moment. So you'll want to experiment with it a little.)

It's hard to tell, but perhaps you're looking for something like:

var myString = String.Join(String.Empty, myList.ToArray());

This will implicitly call the ToString() method on each of the items in the list and concatenate them.

This method helped me when trying to retrieve data from Text File and store it in Array then Assign it to a string avariable.

string[] lines = File.ReadAllLines(Environment.CurrentDirectory + "\\Notes.txt");  
string marRes = string.Join(Environment.NewLine, lines.ToArray());

Hopefully may help Someone!!!!

If your list has fields/properties and you want to use a specific value (e.g. FirstName), then you can do this:

string combindedString = string.Join( ",", myList.Select(t=>t.FirstName).ToArray() );

If you're looking to turn the items in a list into a big long string, do this: String.Join("", myList). Some older versions of the framework don't allow you to pass an IEnumerable as the second parameter, so you may need to convert your list to an array by calling .ToArray().

The direct answer to your question is String.Join as others have mentioned.

However, if you need some manipulations, you can use Aggregate:

List<string> employees = new List<string>();
employees.Add("e1");
employees.Add("e2");
employees.Add("e3");

string employeesString = "'" + employees.Aggregate((x, y) => x + "','" + y) + "'";
Console.WriteLine(employeesString);
Console.ReadLine();

This seems to work for me.

var combindedString = new string(list.ToArray());

String.Join

We can simply convert into a single string using string.join method. The join method concatenate a list of strings into a single string.

string result = String.Join(",", myList);

You can use Humanizer library:

using Humanizer;

Console.WriteLine(new[] { "Alpha", "Beta", "Gamma" }.Humanize());
Console.WriteLine(new[] { "Alpha", "Beta", "Gamma" }.Humanize(","));

The output:

Alpha, Beta & Gamma
Alpha, Beta , Gamma